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Civil Engineering

University of Nebraska - Lincoln

2008

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Quantitative Rrna-Targeted Solution-Based Hybridization Assay Using Peptide Nucleic Acid Molecular Beacons, Xu Li, Eberhard Morgenroth, Lutgarde Raskin Dec 2008

Quantitative Rrna-Targeted Solution-Based Hybridization Assay Using Peptide Nucleic Acid Molecular Beacons, Xu Li, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

The potential of a solution-based hybridization assay using peptide nucleic acid (PNA) molecular beacon (MB) probes to quantify 16S rRNA of specific populations in RNA extracts of environmental samples was evaluated by designing PNA MB probes for the genera Dechloromonas and Dechlorosoma. In a kinetic study with 16S rRNA from pure cultures, the hybridization of PNA MB to target 16S rRNA exhibited a higher final hybridization signal and a lower apparent rate constant than the hybridizations to nontarget 16S rRNAs. A concentration of 10 mM NaCl in the hybridization buffer was found to be optimal for maximizing the difference between …

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Application Of The Modified Log-Wake Law In Open-Channels, Junke Guo, Pierre Y. Julien Sep 2008

Application Of The Modified Log-Wake Law In Open-Channels, Junke Guo, Pierre Y. Julien

Department of Civil and Environmental Engineering: Faculty Publications

The modified log-wake law, which was developed for turbulent boundary layers and pipe flows, is extended to turbulent flows in open-channels. Turbulent velocity profiles in open-channels can be approximated with three components: (1) the law of the wall that results from the constant bed shear stress; (2) the law of the wake that reflects the effects of gravity, secondary currents and bed roughness; and (3) the cubic correction near the maximum velocity. A procedure to determine the four model parameters from velocity measurements while keeping κ = 0.41 is presented. The modified log-wake law compares very well with experimental data …

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Implementing Scc Technology In Nebraska—All About Working Together, Mark D. Lafferty Aug 2008

Implementing Scc Technology In Nebraska—All About Working Together, Mark D. Lafferty

Department of Civil and Environmental Engineering: Faculty Publications

In October 2001, Concrete Industries, Inc. (CI) was working with its admixture supplier to improve our form finish for precast concrete products. They brought us a new product and before long the concrete slump became a 26‐in. (660‐mm) diameter circle. Obviously, this generated a lot of excitement with our production personnel, but we also had to consider what it would take to get architects and engineers comfortable with using it.

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Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth May 2008

Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

Fixed bed biofilm reactors with granular activated carbon (GAC) or glass beads as support media were used to evaluate the influence of short-term (12 h) and long-term (23 days) increases of influent dissolved oxygen (DO) concentrations on biological perchlorate removal. The goal was to evaluate the extent by which chemisorption of oxygen to GAC can enhance the stability of biological perchlorate reduction. Baseline influent concentrations were 50 μg/L of perchlorate, 2 mg/L of acetate as C, and 1 mg/L of DO. Perchlorate removal in the glass bead reactor seized immediately after increasing influent DO concentrations from 1 to 4 mg/L …

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Dynamic Impact Testing Of Crt Wood Posts In A Rigid Sleeve, Steven W. Arens, Ronald K. Faller, John R. Rohde, Karla A. Polivka Jan 2008

Dynamic Impact Testing Of Crt Wood Posts In A Rigid Sleeve, Steven W. Arens, Ronald K. Faller, John R. Rohde, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

Dynamic impact testing was performed on 152-mm x 203-mm (6-in. x 8-in.) CRT wood posts placed in a rigid sleeve at various angles. A total of nine bogie tests were performed with three tests each at 0, 90, and 45 degree rotation angles relative to the strong axis of bending. For each bogie test, the raw acceleration data was obtained from accelerometers and was filtered. Then, force-displacement and energy-displacement graphs were plotted. Based on the results, the properties and strengths of the CRT wood posts at the different impact angles were determined. The results of this study will be the …

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Performance Requirements And Evaluation Procedures For Advance Wide Area Detectors, Anuj Sharma, Matthew Harding, Brad Giles, Darcy M. Bullock, James R. Sturdevant, Srinivas Peeta Jan 2008

Performance Requirements And Evaluation Procedures For Advance Wide Area Detectors, Anuj Sharma, Matthew Harding, Brad Giles, Darcy M. Bullock, James R. Sturdevant, Srinivas Peeta

Department of Civil and Environmental Engineering: Faculty Publications

Dilemma zone protection ideally requires the exact position and speed of all the vehicles approaching the intersection. However, point detectors, typically used to protect vehicle incursion into the dilemma zone, only provide binary information about the presence or absence of a vehicle at a fixed point in space. The information regarding position and speed of the vehicle in subsequent time steps is extrapolated. The extrapolation error increases with the increase in projection time. Wide area detector (WAD) overcomes this drawback by tracking each vehicle at all times until they move out of range. Such a detector has the potential to …

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Assimilating Remote Sensing-Based Et Into Swap Model For Improved Estimation Of Hydrological Predictions, Baburao Kamble, Ayse Kilic Jan 2008

Assimilating Remote Sensing-Based Et Into Swap Model For Improved Estimation Of Hydrological Predictions, Baburao Kamble, Ayse Kilic

Department of Civil and Environmental Engineering: Faculty Publications

An agro-hydrological simulation model is useful for agriculture monitoring and Remote Sensing provides useful information over large area. Combining both information by data assimilation is used in agro-hydrological modeling and predictions, where multiple remotely sensed data, ground measurement data and model forecast routinely combined in operational mapping procedures. Remote sensing cannot observe input parameters of agro-hydrological models directly. A method to estimate input parameters of such model from Remote Sensing using data assimilation has been proposed by Ines [2002] using the SWAP (Soil, Water, Atmosphere and Plant) model. A Genetic Algorithm (GA) loaded stochastic physically based soil-water-atmosphere-plant model (SWAP) was …

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Field Evaluation Of Alternative Real-Time Methods For Estimating Approach Delay At Signalized Intersections, Anuj Sharma, Darcy M. Bullock Jan 2008

Field Evaluation Of Alternative Real-Time Methods For Estimating Approach Delay At Signalized Intersections, Anuj Sharma, Darcy M. Bullock

Department of Civil and Environmental Engineering: Faculty Publications

Vehicle delay at a signalized intersection is among the widely used performance measures of efficiency at a signalized intersection. The Highway Capacity Manual (HCM) uses this performance measure to report the level of service at a signalized intersection. This performance measure is also used to estimate travel time along the arterials. With the advent of technological advances in the field of vehicle detection, real-time measurement of delay at a signalized intersection has become economically and computationally feasible. This paper compares three emerging techniques for estimating approach delay: an Input Output technique (IO), a Hybrid technique, and the HCM delay equation. …

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Pavement Quality Indicators Study, Wayne Jensen Ph.D., Cody Kluver Jan 2008

Pavement Quality Indicators Study, Wayne Jensen Ph.D., Cody Kluver

Mid-America Transportation Center: Final Reports and Technical Briefs

The Nebraska Department of Roads (NDOR) conducts annual examinations of the Nebraska’s interstate and federal high-way pavements. During these examinations, numerous indicators of pavement quality are measured directly or are com-piled from parameters recorded by a vehicle passing over the pavement section. Parameters are documented and analyzed for each one-tenth mile segment. A number of pavement sections where innovative features have been incorporated were selected by the NDOR for comparison to nearby conventional pavement sections. This study used data recorded by the NDOR as well as field observations to develop a comparison between two pavement sections, one with innovative fea-tures …

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Investigation Of Asphalt Pavement Analyzer Testing Program In Nebraska, Minki Hong, Yong-Rak Kim Jan 2008

Investigation Of Asphalt Pavement Analyzer Testing Program In Nebraska, Minki Hong, Yong-Rak Kim

Mid-America Transportation Center: Final Reports and Technical Briefs

The asphalt pavement analyzer (APA) has been widely used to evaluate hot-mix asphalt (HMA) rutting potential in mix design and quality control – quality assurance (QC-QA) applications, because the APA testing and its data analyses are relatively simple, rapid, and easy. However, as demonstrated in many studies and also experienced by the state of Nebraska, the APA testing is in question due to its high testing variability and a lack of sufficient correlation with actual filed performance. The primary objective of this research was to find critical materials and/or mixture design factors affecting APA test results so as to eventually …

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